The type of immunity that is present from birth is: MCQ with Answer and Explanation

Explanation:
Robert Koch, a German physician and microbiologist, formulated Koch's postulates in the late 19th century. These four criteria are designed to establish a causal relationship between a specific microbe and a specific disease. The postulates require that the microbe must be found in all cases of the disease, isolated and grown in pure culture, cause the disease when inoculated into a healthy susceptible host, and be re-isolated from the experimentally infected host.

Explanation:
Biological nitrogen fixation, performed by bacteria (Rhizobium, Azotobacter) and cyanobacteria, reduces N₂ to NH₃. Nitrification oxidizes ammonia to nitrates, denitrification returns N₂, ammonification releases ammonia from organic matter.

Explanation:
Autotrophs produce organic compounds from inorganic CO₂ and water using light energy (photosynthesis). This exactly defines green plants. So both are true, and R explains A.